For those of you who make your own Delrin bushings.....

[FGarbrecht]

do you use a simple 1/4 inch drill bit (assuming they are being made to fit on a standard A mandrel)? A 6.3 mm bit would be a better fit, but I'm not enthused about spending $45 for one.

 

[Sylvanite]

I use a "Letter D" size drill bit for making custom bushings to fit a 7mm (A size) mandrel. It's just under 1/4".

 

[Curly]

Where are you buying your drill bits or is that for solid carbide? How about a buck forty-five? https://www.victornet.com/subdepartments/HS-Jobber-Drills-Metric/1170.html You'll have to get more goodies to reach the $25 minimum though. Even in a small city like Saskatoon I can pick up a TIN coated HssCobalt bit for under $9Can. https://shop.qct.tools/catalogue/product/1362128 There has to be a machine tooling supplier near you that would have them or bring them in for you.

 

[FGarbrecht]

I live in upstate NY and finding anything out of the ordinary locally is a royal PITB. Thanks for the links.

 

[Curly]

Ask a local machine shop where they get tooling from. You can also look at these. https://www.mscdirect.com https://www.kbctools.ca http://www.sowatool.com Searches for machining tools should reveal more. And there is always eBay.

 

[Dusty]

mcmastercarr.com . Little machine shop, or your local Ace hardware may have them.

 

[DrD]

I get my drill bits from Lee Valley or McMaster-Carr. Both have great service.

 

[1shootist]

do you use a simple 1/4 inch drill bit (assuming they are being made to fit on a standard A mandrel)? A 6.3 mm bit would be a better fit, but I'm not enthused about spending $45 for one.

I've made several different sets for myself and friends and have drilled all at 1/4 with no issues.

 

[magpens]

A "D-size" drill bit is 0.246" diameter. . I think that is the same size as the usual A-size pen turning mandrel.

 

[wolf creek knives]

I use an ICS drill bit from Wisconsin and it's a 7mm bit (I buy them locally though for about $5.50). Take a look at page 170 on https://www.icscuttingtools.com/. I glue a 7mm tube into the bushing using a System 3 Epoxy and then turn to what I want on my lathe. It works for me and I can get a bunch of them from a 3' rod I get for under $12.00 on Amazon.

 

[TonyL]

Many excellent sources for bits (here's another one https://www.fairburyfastener.com/). If are using Delrin for non-stick CA bushings that is one thing, if you are using for TBC or mandrel bushings, Corian in more durable. (even PVC is more durable than Delrin). I have both Corian and PVC if you want to try them. PM your address and I will send.
Have said all of the above, many use Delrin just fine from what i understand. I am just offering some alternatives. In fact, I think I have some extra Delrin if you want.

 

[penicillin]

Could someone be very specific about which Delrin they are using, how they make bushings, and how they use them? Pretend that I know nothing and want to go out and buy some Delrin from my local plastics shop. You won't have to pretend.

Can I assume that you buy Delrin rods (dowels), drill them through the center with a D drill or equivalent, square them and cut them off with a miter saw or a parting tool on the lathe? If not, what am I missing about the way that you make them? Are there any tricks I should know about drilling them, other than avoiding heat?

Do you place them flat against the blank when it is ready for sanding and finishing? If not, do you turn a shape on them first? How and when do you use them?

Thanks in advance!